Your problem can be solved by the 3rd software that disk management can not do well.
I recommend you Extend Partition Assistant Professional Edition. This software will finish the work you mentioned flawlessly, I promise.
You can have a try.
After this, you will find this is the best way to extend partition size.
And this software has free edition, you can experience its superiority.
extend-partition.com/extend-system-boot-partition.html
Go and see website, it's helpful.

Chkdsk /r (implies /f as well) is only going to repair file system structures, and it won't change any sizes.

Please note that chkdsk only inspects the physical structure of a disk to make sure that it is healthy. It can repair problems related to bad sectors, lost clusters, cross-linked files, and directory errors. In addition chkdsk can also serve as an early warning that a hard drive is deteriorating. Disks gradually wear out and sectors may become bad. If Chkdsk starts finding bad sectors, that is a sign that a drive may need replacing.